Study of Al–SiO2 Aesthetic Composite Coating on Orthodontic Metal Archwire

Abstract

Nickel–titanium orthodontic wires (NTWs) play an essential role in orthodontic treatment. However, their corrosion and aesthetic properties limit their applications. To improve the aesthetic effects of nickel–titanium orthodontic archwires, we prepared aluminium–silicon dioxide (Al–SiO2) as a biocompatible layer coated onto the NTWs. The Al–SiO2 coating was first fabricated using physical vapor deposition magnetron sputtering, and its physicochemical and biocompatibility properties were investigated. Al–SiO2 layers were well coated on the NTWs. The corrosion currents in the nickel–titanium (NiTi) control, Al–SiO2-coated NiTi experimental, stainless steel (SS) control and Al–SiO2-coated SS experimental groups were 23.72 μA cm−2, 1.21 μA cm−2, 0.22 μA cm−2 and 0.06 μA cm−2, respectively. Al–SiO2-coated NTWs with reduced corrosion current density indicated that the preparation of Al–SiO2 coating on the surface of NiTi and SS could reduce the tendency of electrochemical corrosion. The friction coefficients of orthodontic wires in the NiTi control, NiTi experimental, SS control, and SS experimental groups were 0.68, 0.46, 0.58 and 0.45, respectively. A low friction coefficient was observed in the Al–SiO2-coated NTWs, and the reduced friction coefficient improved the efficiency of orthodontics. Furthermore, the excellent biocompatibility of the NTWs and SS coated with Al–SiO2 indicates that Al–SiO2 as a novel aesthetic layer could improve the physicochemical properties of NTW and SS without causing cytotoxicity, which has considerable potential for modification of NTW and SS surfaces.

Functional Surface Coatings on Orthodontic Appliances: Reviews of Friction Reduction, Antibacterial Properties, and Corrosion Resistance

“…However, Ag and ZnO, as classic antimicrobial coatings, have also been repeatedly proven to have excellent antimicrobial properties and biocompatibility, and have been put into clinical application for a longer time and with good results [ 109 , 139 ]. Interestingly, Al compound and composite coatings generally perform better in corrosion-resistant coatings, such as Al 2 O 3 coatings [ 30 , 158 ], Al 2 O 3 /TiO 2 multi-layer coatings [ 158 ], and Al-SiO 2 coatings [ 70 ]. In particular, Al-SiO 2 coatings not only significantly reduce the corrosion on the surface of substrates, but also have the advantages of friction reduction, wear resistance, and biocompatibility [ 70 ].…”

“…Interestingly, Al compound and composite coatings generally perform better in corrosion-resistant coatings, such as Al 2 O 3 coatings [ 30 , 158 ], Al 2 O 3 /TiO 2 multi-layer coatings [ 158 ], and Al-SiO 2 coatings [ 70 ]. In particular, Al-SiO 2 coatings not only significantly reduce the corrosion on the surface of substrates, but also have the advantages of friction reduction, wear resistance, and biocompatibility [ 70 ]. This kind of multilayer and composite material is also gradually becoming a research trend in recent years, which might be suitable for application.…”

“…In contrast, the friction reduction properties of Al have not been adequately studied. A reduction in the CoF is observed in Al-SiO 2 -coated NiTi and SS archwires compared to the uncoated ones [ 70 ]. Therefore, Al-SiO 2 composite coatings may also be used to reduce the friction of orthodontic archwires in the future.…”

Performance improvement and optimization of nano-based coatings

“…For PAGO preparation 2 mL of aniline was measured and dissolved in 100 mL of deionized water, weighing 60 mg of GGO, which was also added to deionized water and stirred with a magnetic stirrer for 1 h. An appropriate amount of ammonium sulfate solution was taken and dissolved in 20 mL of hydrochloric acid, according to the amount ratio of aniline and ammonium persulfate [4] . 1:1 was added to the mixed solution under IOP Publishing doi:10.1088/1742-6596/2775/1/012016 2 the condition of an ice water bath (< 4℃) and the duration of 24 h and 12 h. Then with anhydrous ethanol, water was deionized to filtrate pH 6, filter, and produce dark green PANI / graphene oxide, (PAGO) [5] .…”

Corrosion of Fixed Orthodontic Appliances: Causes, Concerns, and Mitigation Strategies

“…The best wear behavior was found for Al 2 O 3 (or TiN)-coated archwires against metal brackets (CoF = 0.207 and 0.372, respectively). Wu et al [435] deposited Al-SiO 2 coatings by magnetron sputtering that smoothed the surface of NiTi and SS archwires and enhanced their overall corrosion resistance with no apparent cytotoxicity.…”